The advantages of jQuery are:
Simple and easy to use.
Has extensive documentation in the form of blogs, code snippets, tutorials, and other resources
Simple and clean syntax.
Open coding standards, intuitive.
Deals with cross-browser issues without the developer having to worry about them.
Lightweight with the core library being just 24kb.
Open-source library.
Exhaustive set of animations and effects.
Extensible and fast.
It can be optimized for search engines for better SEO.